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In this
segment of the program, we will discuss contraindications and precautions
to the administration of smallpox vaccine. These contraindications and
precautions are applicable for situations of nonemergency use of smallpox
vaccine.

In an outbreak,
for persons exposed or potentially exposed to a person with smallpox,
there are no contraindications to vaccination.

Smallpox
vaccine contains live vaccinia virus, which is administered into the superficial
layers of the skin. A successful vaccination produces a lesion on the
skin that contains vaccine virus for up to 3 weeks. The vaccine virus
can be transmitted to household and other close contacts. So, in the absence
of smallpox cases, candidates for vaccination must be screened for contraindications
very carefully. Certain medical conditions in the person's household contacts
must also be considered as contraindications for vaccination.

As with
all vaccines, smallpox vaccine is contraindicated for persons who have
experienced a serious allergic reaction to a prior dose of vaccine, or
to a vaccine component. By serious allergic reaction, we mean anaphylaxis
or symptoms of an anaphylaxis-like reaction, such as generalized urticaria,
wheezing, or difficulty breathing.

In addition
to live vaccinia virus, reconstituted Dryvax vaccine contains trace amounts
of the antibiotics polymyxin B, streptomycin, tetracycline, and neomycin.
It also contains phenol as a preservative. People with serious allergy
to any of these products should not be vaccinated. The newer cell culture
vaccines do not contain antibiotics. No smallpox vaccine available in
the United States contains penicillin.

People with
significant immunosuppression, should not receive smallpox vaccine. Replication
of vaccinia virus can be enhanced among people with immunodeficiency diseases
and immunosuppression, and result in serious adverse reactions. Also,
because the recent vaccination site contains live virus that can be transmitted
to other individuals, people with household contacts who are immunosuppressed
should also not be vaccinated in nonemergency situations.

Significant
immunosuppression can be caused by many diseases, including leukemia,
lymphoma, generalized malignancy; solid organ or stem cell transplantation;
and humoral or cellular immunity disorders, including HIV infection.

Drugs that
can cause immunosuppression include alkylating agents, antimetabolites,
radiation, or high-dose corticosteroid therapy. Prednisone doses of 2
milligrams per kilogram of body weight per day or higher or 20 milligrams
per day or higher for 14 days or more should be considered immuno suppressive.
As with other live vaccines, those on high levels of these drugs should
not be immunized for three months after their last dose.

Live viral
vaccines are contraindicated during pregnancy. Smallpox vaccine should
not be administered to pregnant women or people with pregnant household
contacts for nonemergency indications. Pregnancy should also be avoided
for at least a month after vaccination. Women who are breastfeeding should
not be vaccinated, because the close contact that occurs during this activity
could increase the chance of transmission of the vaccine virus to the
breastfeeding infant.

Because
of the increased risk for eczema vaccinatum, smallpox vaccine should not
be administered to people with eczema or atopic dermatitis or a past history
of these conditions. People who have a HOUSEHOLD CONTACT with eczema or
atopic dermatitis or a history of these conditions should also not be
vaccinated.

People with
other types of acute, chronic, or exfoliative skin conditions, such as
psoriasis, contact dermatitis, or varicella zoster might be at higher
risk for disseminated skin rashes from the vaccine, although these rashes
are generally not as severe as eczema vaccinatum. People with exfoliative
skin conditions should not be vaccinated until the condition is under
good control or resolves.

Children
less than 12 months of age should not be vaccinated. All vaccinated people
should take precautions to prevent virus transmission to young children
and other household contacts. As with all vaccines, vaccination should
be deferred for people with moderate or severe acute illnesses.

One reminder:
in the event of an actual exposure to smallpox, vaccination may be considered
for individuals who otherwise have contraindications, because the benefits
of vaccination would most likely outweigh the risks.

In summary,
smallpox vaccine should not be administered to persons known to have a
serious allergy to a prior dose of vaccine or vaccine component; persons
with significant immunosuppression from any cause; someone with an immunosuppressed
household contact; a woman who is pregnant or attempting to become pregnant,
or someone with a household contact who is pregnant; and women who are
breastfeeding.

Smallpox
vaccine should not be administered to persons with a diagnosis of eczema
or atopic dermatitis, including eczema or atopic dermatitis that is not
currently active; or a person who has a household contact who has eczema
or atopic dermatitis or a history of these diseases; persons with other
extensive exfoliative skin conditions; children less than 12 months of
age; and persons with a moderate or severe acute illness.

A careful
medical history for contraindications to vaccination should be done for
EVERY person prior to vaccination. Additional information about contraindications
and precautions for smallpox vaccine can also be found on the CDC websites.